Helical slide fastener



Se t. 22, 1964 H. WILCKEN HELICAL SLIDE FASTENER Filed Aug. 2, 1965 ueoWH CKEN hi: 4 Horne United States Patent 3,149,388 HELICAL SLIDEFASTENER Hugo Wilcken, Curau uher Luheclr, Germany, assignor toOpti-Holding A.G., Glarus, Switzerland, a corporation of SwitzerlandFiled Aug. 2, 1963, Ser. No. 299,557 Claims priority, applicationGermany Aug. 4, 1962 4 Claims. (Cl. 24-2651) The invention relates to ahelical spring type slide fastener in which two flattened helicalsprings made of a wire of thermoplastic material are sewed each onesidedly to a carrier ribbon to form an ironing protection on the sideremote of the ribbon, said helical springs having coupling surfacesarranged at their opposing face sides which in longitudinal direction ofthe slide fastener project on both sides beyond the diameter of thewire.

In known helical spring type slide fasteners, as described above, theironing protection for the helical springs made of wires ofthermoplastic material which are one sidedly connected to a carrierribbon is achieved in such a manner that the free upper surface of thehelical spring is covered with a narrow tape or a string which togetherwith the convolutions of the helical spring are connected to the carrierribbon by sewing stitches. According to another known embodiment theline of convolutions is sewed to the carrier ribbon by a double stitchseam, or a so-called vamping seam, in which the lower thread loops ofthis scam are covering the free upper surface as an ironing protection.Even if the helical spring is provided with an inner core it cannot beavoided that the tapeor lamellar-like ironing protection is shiftedtransversely towards one or the other side of the slide fastener, whenopening or closing the same, whereby the intended ironing protection isnullified, or at least partly nullified, and besides this, theappearance of the slide fastener is impaired, since the cover extendslongitudinally in waves caused by unavoidable transverse displacements.

Therefore the main object of this invention is to provide a slidefastener of the type described in which transverse displacements of theironing protection cover on the convolutions of the helical spring areavoided.

Another object of this invention is to provide a slide fastener of thetype described in which additionally a firm interlocking engagement ofthe coupling surfaces is obtained without the necessity to provide acore for this purpose.

The first mentioned problem of the invention is solved in that in ahelical spring type slide fastener as described above the convolutionparts of the helical spring disposed remote of the carrier ribbon aredeformed in the middle in an arcuate manner in a direction towards thecarrier ribbon, and that the longitudinally extending groove formed bysuch deformations serves to receive a textile ironing protection.

In this embodiment the helical springs may also, if desired, beadditionally provided with a core which, however, must allow thedeformation of the convolution portions of the helical spring withoutexerting an inadmissible resilient restoring force upon the deformedportions.

According to the invention the flattened helical springs are provided atthe side remote of the carrier ribbon with a longitudinally extendinggroove receiving an ironing protection in form of narrow sewed-on tapesor strings, or in form of lower thread loops of a double stitch orvamping seam, or in form of a plurality of parallel backstitch seams,whereby this ironing protection, due to the connecting sewing stitchescannot be displaced transversely of the slide fastener, thus obtainingan unobjectionable ironing protection and an apice pearance of the slidefastener which will always remain constant.

The deformations of the helical spring convolutions forming the grooveinclude another advantage in that without any drawbacks the core, knownper se, may be omitted which serves the purpose to maintain the couplingsurfaces of the two slide fastener members in a firm interlockingengagement and thus decreasing the danger of breaking the joint.

For the same purpose the deformations of the helical spring convolutionsare, according to the invention, shaped in such a way that they form aninterior profiled spaced into which always the coupling surfaces of theopposed helical spring convolutions interfit, whereby the couplingsurfaces of the one helical spring member are firmly urged towards thecoupling surfaces of the other helical spring member by the resiliencyof the deformed convolution portions.

Now, if such row of links formed by the helical spring made of asuitable wire of thermoplastic material, for example polyamide,polyurethane, polyester, or the like having resilient characteristicsare connected by sewing them to one side of a carrier ribbon the threadstend to draw the longer convolution portions of the helical springopposed to each other together, whereby the profile of the interiorspace of the convolutions disposed in front of the coupling surfaces isreduced somewhat. Whenever a pair of slide fastener members of this typeis drawn together by a slide the enlarged coupling surfaces projectingbeyond both sides of the wire are engaging these interior convolutionspaces and try to expand the respective convolution space somewhatagain, in other words the corresponding portions of the deformationsfacing the coupling surfaces resiliently urge the coupling surfaces ofthe pair of slide fastener members together, so that the couplingsurface cannot be decoupled. This means that no relative transversedisplacements of the pair of slide fastener members can take place, andthus the safety against breaking the connection is assured. The couplingsurfaces may be formed in any suitable manner either with plane orconcave surfaces, as it is known per se. Now the invention shall bedescribed in connection with the attached drawing showing severalembodiments by way of example.

In the drawings:

FIG. 1 is a pmtial top view of a helical spring type slide fastener inwhich the slide fastener members are in their interlocked positions,

FIG. 2 is a cross sectional view along the line 11-11 of FIG. 1 on astrongly enlarged scale,

FIG. 3 is a partial longitudinal section along line IHIH of FIG. 2, and

FIG. 4 is a cross sectional view of a slide fastener member of asomewhat altered embodiment of the convolutions of the helical spring,also shown in a strongly enlarged scale.

According to the embodiments shown by way of example the pair ofinterlocking link rows of a slide fastener consists of flattened helicalsprings 1 and 2 each being sewed close to the edge of a carrier ribbon 3and 4. The convolutions of the flattened helical springs are providedwith coupling surfaces 5 and 6 lockably interengaging each other. Thecoupling surfaces may be plane or concave as is known per se.

In accordance with the invention the convolutions of the slide fastenerinterlocking link rows are, according to the example shown in FIGS. 1-3,provided with armate deformations 1a and 2a at the side remote of thecarrier ribbons. These deformations may be bent downwardly to such anextent that the upper convolution portions approach those convolutionportions having contacting engagement with the carrier ribbons 3 and 4,or

a, 1 as, sea

1 3 even overlap these convolution portions. By means of .ddesedeformations 1a and 2a longitudinally extending {grooves are formed inthe interlocking link rows of the helical springs. The depth of thedeformations may be :selected at liberty, so that narrow tapes orstrings of texwtile material may be introduced when sewing theinterlocking link rows of the helical springs to the carrier ribbons.The inserted narrow tapes or strings are sewed to the carrier ribbons 3and 4 together with the convolutions of the helical springs by sewingstitches 7a. In the right hand half of FIG. 2 the insertion in thegroove consists of a string! which may be formed in such a way that notonly the groove but also the adjacent portions of the individualconvolutions of the helical spring are covered. In the left hand half ofFIG. 2 the connection I with the carrier ribbon 3 is accomplished by aplurality of parallel seams 8, in which the sewing threads, contrarytfhe illustrated embodiment, may be'chosen with such a ahickness thatthe finished seam will also form an ironing protection for the helicalspring consisting of thermoplastic material. Also double backs't'i'tchscams or vamping seams may be used for connecting the link row with thecarrier ribbon, in which the lower thread loops of these seams arefilling, or at least nearly filling the grooves formed .by thedeformations.

According to the embodiment shown in FIG. 4 the deformations 1a may notonly be provided in the upper convolution portions of the helical springbut also in the convolution portions adjacent the carrier ribbon, sothat the convolutions in a cross-sectional view will have substantiallythe form of a lying eight. In this case also ahe sewing of'the link rowsof the helical springs to the :carrier ribbons is accomplished in thesame manner as described in connection with FIGS. 1-3. The groove:formed by the deformations is filled with a textile ironing protection.If merely an ironing protection is to be obtained, which is safeguardedagainst transverse shifting by engaging the groove, the inner space ofthe convolutions of the helical spring may also be provided with afiller core,-which is knownper se, serving the purpose to maintain thecoupling surfaces of the two fastener membersywhen brought intoengagement, in interengaging surface contact.

According "to another embodiment of the invention in which a :iillercore is to be omitted the procedure for obtaining the same effect issuch that the deformations 1a, and 2a, or the deformations of theconvolution portti'ens disposed in front of the coupling surfaces 5 and6 respectively, will form a profiled inner space 9, or respectively, ofthe helical spring convolutions into which the coupling surfaces of theopposed helical spring convolutions fit in such a manner that, due tothe resiliency of the deformed convolution portions facing the couplingsurfaces, the coupling surfaces of the one helical spring are maintainedin contacting engagement with the coupling surfaces of the other helicalspring. Advantageously the procedure, when connecting the helicalsprings to the carrier ribbons 3 and 4, is such that the connectingseams 7a will cause the opposed convolution portions to approach eachother to such an extent that the profile of the inner spaces 9 and 10 issomewhat reduced. Now, if the coupling surfaces, upon drawing togetherthe link rows of the slide fastener by means of a slide, are broughtinto interlocking engagement the profiles of the inner spaces 9 and 10are elastically expanded again somewhat, whereby the coupling surfacesare constantly urged into resilient mutual contacting engagement. Theembodiment shown in FIGS. 13 as well as the embodiment shown in FIG. 4may be formed in such a way.

. In accordance with the above described procedure an ironing protectionfor the link rows of the helical springs consisting of thermoplasticmaterial is obtained and in addition the coupling surfaces of the slidefastener members are constantly urged into interlocki contactingengagement without the necessity to provid a filler core being resilientin transverse direction. Thus transverse shifting of the locking linksrelative to one another in a transverse direction is also preventedwhereby the safety against unintentional tearing the slide fastenermembers apart is assured.

What I claim is:

1. A helical spring type fastener, comprising two carrier ribbonsextending in parallel relation; two flattened helical springs formed bya wire of thermoplastic material and being disposed each adjacent thefacing edges of each of said carrier ribbon extending longitudinallyalong one side thereof; arcuate, inwardly directed deformationsformed'in the middle of one 'of the flattened convolution portions ofsaid helical springs, said deformations forming a longitudinallyextending groove at the side of said helical spring which is facing awayfrom said carrier ribbon, a textile ironing protection accommodated andextending within said groove projecting with its upper surface beyondthe adjacent crests of said deformed convolution portions, a seam ofsewing stitches extending along said groove formed by said deformations,and embracing each convolution holding them spaced apart in uniformspacings corresponding substantially to the cross sectional dimension ofsaid wire, and coupling surfaces provided at each of the convolutionportions of the helical springs which are facing each other, saidcoupling surfaces being formed by widened portions of said wireprojecting beyond both sides thereof.

2. A helical spring type fastener, comprising two carrier ribbonsextending in parallel relation; two flattened helical springs formed bya wire of thermoplastic material and being disposed each adjacent thefacing edges of each of said carrier ribbon extending longitudinallyalong one side thereof; arcuate, inwardly directed deformations formedin the middle of one of the flattened convolution portions of saidhelical springs, said deformations forming a longitudinally extendinggroove at the side of said helical spring which is facing away from saidcarrier ribbon, a textile ironing protection accommodated and extendingwithin said groove projecting with its upper surface beyondthe adjacentcrests of said deformed convolution portions, a seam of sewing stitchesextending along said groove formed by said deformations, and embracingeach convolution holding them spaced apart in uniform spacingscorresponding subtsantially to the cross sectional dimensions of saidwire, and coupling surfaces provided at each of the convolution portionsof the helical springs which are facing each other, said couplingsurfaces being formed by widened portions of said wire projecting beyondboth sides thereof, profiled inner spaces being formed by said deformedconvolution portions being contoured so as to resiliently act upon theinterengaging coupling surfaces urging them into mutual contactingengagement when coupled and thereby preventing relative transverseshifting of said helical springs.

3. A helical spring type slide fastener, comprising two carrier ribbonsextending in parallel relation, two flattened helical springs formed bya wire of thermoplastic material and being disposed each adjacent thefacing edges of each of said carrier ribbons extending longitudinallyalong one side thereof, arcuate inwardly directed deformations formed inthe middle of the diametrically opposed flattened convolution portionsof said helical springs, said row of deformations facing away from saidcarrier ribbon forming a longitudinally extending groove, a textileironing protection accommodated and extending within said grooveprojecting with its upper surface beyond the adjacent crests of saiddeformed convolution portions, a seam of sewing stitches extending alongsaid groove formed by said deformations, and embracing each convolutionholding them spaced apart in uniform spacings correspondingsubstantially to the cross sectional dimension of said wire, andcoupling surfaces provided at each of the convolution portions of bothhelical springs which are facing each other, said coupling surfacesbeing formed by widened portions of said wire projecting beyond bothsides thereof.

4. A helical spring type slide fastener, comprising two carrier ribbonsextending in parallel relation, two flattened helical springs formed bya wire of thermoplastic material and being disposed each adjacent thefacing edges of each of said carrier ribbons extending longitudinallyalong one side thereof, arcuate inwardly directed deformations formed inthe middle of the diametrically opposed flattened convolution portionsof said helical springs, said row of deformations facing away from saidcarrier ribbon forming a longitudinally extending groove, a textileironing protection accommodated and extending within said grooveprojecting with its upper surface beyond the adjacent crests of saiddeformed convolution portions, a seam of sewing stitches extending alongsaid groove formed by said deformations, and embracing each convolutionholding them spaced apart in uniform spacings correspondingsubstantially to the cross sectional dimension of said wire, andcoupling surfaces provided at each of the convolution portions of bothhelical springs which are facing each other, said coupling surfacesbeing formed by widened portions of said wire projecting beyond bothsides thereof, profiled inner spaces being formed by said deformedconvolution portions being contoured so as to resiliently act upon theinterengaging coupling surfaces urging them into mutual contactingengagement when coupled and thereby preventing relative transverseshiftin of said helical springs.

References Cited in the file of this patent UNITED STATES PATENTS3,022,803 Berberich Feb. 27, 1962 FOREIGN PATENTS 1,232,000 France Oct.4, 1960

1. A HELICAL SPRING TYPE FASTENER, COMPRISING TWO CARRIER RIBBONSEXTENDING IN PARALLEL RELATION; TWO FLATTENED HELICAL SPRINGS FORMED BYA WIRE OF THERMOPLASTIC MATERIAL AND BEING DISPOSED EACH ADJACENT THEFACING EDGES OF EACH OF SAID CARRIER RIBBON EXTENDING LONGITUDINALLYALONG ONE SIDE THEREOF; ARCUATE, INWARDLY DIRECTED DEFORMATIONS FORMEDIN THE MIDDLE OF ONE OF THE FLATTENED CONVOLUTION PORTIONS OF SAIDHELICAL SPRINGS, SAID DEFORMATIONS FORMING A LONGITUDINALLY EXTENDINGGROOVE AT THE SIDE OF SAID HELICAL SPRING WHICH IS FACING AWAY FROM SAIDCARRIER RIBBON, A TEXTILE IRONING PROTECTION ACCOMMODATED AND EXTENDINGWITHIN SAID GROOVE PROJECTING WITH ITS UPPER SURFACE BEYOND THE ADJACENTCRESTS OF SAID DEFORMED CONVOLUTION PORTIONS, A SEAM OF SEWING STITCHESEXTENDING ALONG SAID GROOVE FORMED BY SAID DEFORMATIONS, AND EMBRACINGEACH CONVOLUTION HOLDING THEM SPACED APART IN UNIFORM SPACINGSCORRESPONDING SUBSTANTIALLY TO THE CROSS SECTIONAL DIMENSION OF SAIDWIRE, AND COUPLING SURFACES PROVIDED AT EACH OF THE CONVOLUTION PORTIONSOF THE HELICAL SPRINGS WHICH ARE FACING EACH OTHER, SAID COUPLINGSURFACES BEING FORMED BY WIDENED PORTIONS OF SAID WIRE PROJECTING BEYONDBOTH SIDES THEREOF.